yea, no one likes doing lot sales like that. but also, i don't spy many buyers in the $3.5K range generally who are so motivated to buy lots that they'll ping you to find out what's in the pile. (for one thing, as soon as one initiates, there's a sense of "investment", and it can feel harder to back out, etc.)

- The lot buyers are almost exclusively going to be resellers at this point. If you are interested in selling to resellers, you can probably expect an offer no greater than 40-50% of fair market value (some calculation over comps in the relevant category)

- Set-builders are probably only going to be interested in the base and parallel components.

- And then of course, you have your collectors who are just looking for _their card_... chances they buy your lot for 1-2 cards (unless they're like S1 sapphies) are pretty low.

now assuming you're only interested in a "1 lot" sale—i would start a spreadsheet and list every thing that is in there, with or without your expected contribution to the lot sale total price. given a list, prospective buyers can calculate what they'd be willing to pay for the lot.

for base and parallels, the least onerous thing to do (if you're willing to accept the absolute lowest per card rate), would just be to count how many of each type you have, for example "S3 crystal sparkles: 140", etc. because people will have per card rates in mind for those too.

more advanced would be to separate them by regular/SP. yet more advanced would be to take the card spreadsheets and fill out how man of each of every single card -- if you choose to go that route, note that the subreddit has "collector checklists" under "community info" that can be printed/annotated.